As grass growth slows, rust will be one of the lawn fungi we are dealing with. Rust appears as an orange or yellowish-orange powder (spores) on grass leaf blades, especially in late summer to early fall when the weather is dry. Rust typically develops on lawns growing very slowly. Overall, the turf may assume a yellow, red, or brown appearance. Rust spores can easily be tracked into homes. Other turf diseases such as dollar spot and brown patch are also prevalent.

Low fertility (in particular nitrogen) and high temperatures slow down turf growth, allowing rust to develop. Heavy dew and light, frequent rainfall add to the ideal conditions for rust to develop. Warm, cloudy, humid weather followed by hot, sunny weather also favors rust development on lawns. Kentucky bluegrass, perennial ryegrass, and tall fescue are all affected, depending on cultivars. Rust spreads through air, water, shoes, equipment, and sod. Rust may weaken turfgrasses and make them more susceptible to other problems. Fungicides are rarely suggested on home lawns for rust control. Focus on the listed cultural practices described above.